Silver halide emulsions containing hydroxy carboxylic acid derivatives as fog inhibitors



United States Patent SILVER HALIDE EMULSIONS CONTAINING HY- DROXY CARBOXYLIC ACID DERIVATIVES AS FOG INHIBITORS Wilbert J. Humphlett, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed Nov. 25, 1964, Ser. No. 413,962

19 Claims. (Cl. 96109) ABSTRACT OF THE DISCLOSURE Photographic silver halide emulsions containing derivatives of hydroxy carboxylic acids as antifoggants and elements comprising such emulsions are disclosed.

This invention relates to stabilized photographic compositions, and more particularly, to photographic silver halide emulsions containing novel fog-inhibiting agents.

It is well known that photographic emulsions on stor age tend to lose sensitivity and to become spontaneously developable without exposure to light. There is normally a detectable amount of the silver salt reduced during development in the areas where no exposure was given, this commonly being called fog, and sometimes chemical fog where it is necessary to distinguish between it and the effects of accidental exposure to radiation. In this invention, I am concerned with the former, namely, chemical fog. Also, the present invention should be distinguished from methods for preventing color fog or stain resulting in color photography from oxidized color developer at places where silver halide is not reduced.

Fog as contemplated herein depends both on the emulsion and the conditions of development. For a given emulsion, fog increases with the degree of development. With constant development conditions, fog tends to increase with time, temperature and relative humidity of storage conditions. It is common practice to make accelerated tests of the stability of photographic emulsions by storage at increased temperature or humidity, or both. It is of course desirable to have emulsions as stable as possible under the conditions of high temperature and humidity which may occur in tropical climates, for example. Fog usually appears over the whole area of the sensitive coating, but when severe, it frequently is nonuniform. Fog may also be caused by exposure to chemicals, for example, hydrogen sulfide and other reactive sulfur compounds, hydrogen peroxide vapor, and strong reducing materials. While antifoggants and stabilizers may protect, to some extent, against such effects, it is normally understood that an antifoggaut protects against spontaneous growth of fog during prolonged storage or storage at high temperatures and humidities, or during development to maximum contrast and speed, or both.

It is hence an object of this invention to inhibit fog formation in photographic silver halide emulsions with novel emulsion addenda.

It is also an object of this invention to provide new photographic silver halide emulsions containing antifoggant addenda that do not cause objectionable desensitization of the emulsion.

These and other objects of the invention are accomplished by incorporating into photographic silver halide 3,396,028 Patented Aug. 6, 1968 emulsions antifoggant amounts of derivatives of hydroxy carboxylic acids having Formulas I and H,

( LH l AH wherein: M and Z are each hydroxy radicals or acyloxy radicals and 0 II (0 GR wherein R is an alkyl radical or an aryl radical) X is a hydrogen atom, an acyloxymethyl radical ll (CH2OO Ii, wherein R is an alkyl radical or an aryl radical) or a carbinol radical (--CH OH); Y is a carboxy radical a carbamyl radical or a radical having the formula wherein R is an alkyl radical (more generally having 1 to 2 carbons, particularly when Z is a hydroxyl radical); A is a carbinol radical, a radical having the formula 3 OOR Hence, at least one of A, Y and Z of Formula II forms a carbamyl or an ester radical. Typical useful antifoggant 3 addenda can be represented by the following more subgeneric formulas:

l I 0, orromq, (CH M wherein: R is an alkyl radical having 1 to 2 carbon atoms; R and R are each an alkyl radical which more generally has 1 to 8 carbon atoms or a phenyl radical, including substituted phenyl radicals; R is an alkyl radical which more generally has 1 to 8 carbon atoms or a hydrogen atom; p is an integer of 2 to 3; and q is an integer of 1 to 5. Other subgeneric formulas defining antifoggant addenda of the invention included within generic Formulas I and II can be formulated. The alkyl substituents described above suitably have 1 to 20 carbon atoms, and preferably 1 to 8 carbon atoms, including methyl, ethyl, isopropyl, butyl, heptyl, octyl, decyl, octadecyl, eicosyl and the like. The aryl substituents described above include such radicals as phenyl, tolyl, naphthyl and the like, phenyl being preferred.

As described above, a wide variety of amide or esterhydroxy carboxylic acid derivatives can be utilized as antifoggant addenda for photographic silver halide emulsions. Such compounds can be prepared by conventional amidation and esterification techniques with such saturated, aldehyde radical-free, hydroxy carboxylic acids as glyceric, erythronic, arabonic, lyxonic, ribonic, xylonic, gluconic, galactonic, mannonic, gulonic, tartaric, glucoguloheptonic and the like hydroxy carboxylic acids.

Literature references describing the preparation of typical antifoggant addenda of the invention include:

(a) J. Am. Chem. Soc., 37, 345 (1915) (b) I. Am. Chem. Soc., 55, 2512 (1933) (c) I. Am. Chem. Soc., 62, 1074 (1940) (d) J. Am. Chem. Soc., 69, 915 (1947) (e) J. Org. Chem, 18, 952 (1953) (f) I. Am. Chem. Soc., 78, 2825 (1956) (g) Helv. Chim., Acta, 34, 2343 (h) J. Am. Pharm. Assoc., 28, 364 (1949) (i) US. Patent 2,380,444

Other references can be found in the liteurature describing the preparation of the present feature addenda.

The addenda of the invention described above can be added to the photographic silver halide emulsions for purposes of increasing the stability thereof. More specifically the subject addenda serve as emulsion antifoggants. Many antifoggant addenda cause substantial desensitizations or loss in speed of the emulsion when employed therein antifoggant amounts. However, with the subject addenda there is no objectionable loss of speed imparted to emulsions.

The particular quantity of the present stabilizers used in a given emulsion can vary, depending upon the effects desired, degree of ripening, silver content of the emulsion, etc. I have found that generally from about 5 to 100 grams of the feature addenda per mole of silver halide are quite adequate to accomplish the desired stabilization, with about 10 to 50 grams of the addenda per mole of silver halide being preferred. Exposure of the treated emulsion in conventional photographic testing apparatus, such as an intensity scale sensitometer, will reveal the most advantageous concentrations for the present stabilizers in that particular emulsion. Such techniques are Well understood by those skilled in the art.

The addenda of the invention can be added to photographic emulsions using any of the well-known techniques in emulsion making. For example, they can be dissolved in a suitable solvent and added to the silver halide emulsion, or they can be added to the emulsion in the form of a dispersion similar to the technique used to incorporate certain types of color-forming compounds (couplers) in a photographic emulsion. Techniques of this type are described in Jelley et al., US. Patent 2,322,027, issued June 15, 1943, and Fierke et al., US. Patent 2,801,171, issued July 30, 1957. The solvent should be selected so that it has no harmful effect upon the emulsion in accordance with usual practice, and generally solvents or diluents which are miscible with water are to be preferred.

In addition to the subject antifoggant addenda, the photographic emulsions of the invention can contain the usual well-known emulsion addenda such as spectral sensitizers, speed increasing materials (e.g. polyalkylene glycols, cationic compounds, thioethers, etc.), coating aids gelatin hardeners, plasticizers and the like.

The stabilizer addenda of the invention can be used in various kinds of photographic emulsions. They can be used with silver halide emulsions chemically sensitized with compounds of the sulfur group, with noble metal salts such as gold salts, reducing agents or combinations of these. In addition to being useful in orthochromatic, panchromatic, and infrared sensitive emulsions, they are also useful in X-ray and other nonspectrally sensitized emulsions. They can be'added to the emulsion before or after any spectral sensitizing dyes which may be used. Various silver salts can be used as the sensitive salt such as silver bromide, silver iodide, silver chloride, or mixed silver halides such as silver chlorobromide or silver bromoiodide. The subject addenda can be used in emulsions intended for color photography, for example, emulsions containing color-forming couplers or emulsions to be developed by solutions containing couplers or other colorgenerating materials, dye developer systems and dye bleach systems.

In the preparation of the silver halide dispersions employed for preparing silver halide emulsions, there can be employed as the dispersing agent for the silver halide in its preparation, gelatin or some other colloidal material such as colloidal albumin, a cellulose derivative, or a synthetic resin, for instance, a polyvinyl compound, although gelatin is preferred. Mixtures can be used (e.g. gelatin-l-polyacrylamide).

The above-described emulsions of the invention can be coated on a Wide variety of suports in accordance with usual practice. Typical supports for photographic elements of the invention include cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethylene terephthalate film and related films or resinous materials, as well as glass, paper, polyethylene coated paper, metals, wood and others.

The invention is further illustrated by the following examples.

Example 1 A high-speed sulfur-gold sensitized gelatino silver bromide emulsion was prepared, various antifoggant addenda of the invention were added to separate portions thereof, and the resulting compositions were coated on cellulose acetate film supports at coverages of 459 mg. of silver per square foot and 1040 mg. of gelatin per square foot. Similar photographic elements were prepared without the feature antifoggant addenda for purposes of comparison. Samples of the prepared photographic elements were incubated for 7 or 14 days at F. and 50% relative humidity, exposed in the form of film strips in an intensity scale sensitometer (Eastman IB sensitometer), developed for 5 minutes at 68 F., and then fixed, washed and dried in the usual manner. Test samples were also exposed in the sensitometer directly after coating for purposes of comparison. The developer had the following formula:

TABLE B-Cntinued Cone. of

feature addenda DEVELOPER Feature addenda: (g./mo1e AgX) N h l Grams Ethyl L-arabonate 5 -met y -p-am1nophenolsulfate 2.5 Ethyl DLarabonate 45 glygroqumone Methyl D-anabonate tetraacetate 45 o Sulfite (anhydrws) n-Propyl D-arabonate tetraacetate 45 5041111151 metaborafe Octahydrate Isopropyl D-arabonate tetraacetate Potassmm brmmd? 2,3,4,6-tetraacetyl-D-gluconic acid mono- Water to make one hter. 10 hydrate 3 The results of the sensitometric tests are summarized by 45 the data set out in Table A below with respect to rela- Dgalactonamlde tive speed, gamma and fog. In Table A below, the Methyl D'galactonate speeds indicated are a function of the exposure necessary 15 Ethyl 'Ddnalmonate 45 to give a density of 0.2 above background fog, the initial y -"l- 6 control speed being taken as 100 in each case; and the D-lyxonamide 6 concentrations of addenda are indicated as grams of ad- L-erythrono-v-lactone 45 denda per mole of silver halide. Methyl L-arabonate 9, 25

TABLE A Fresh Test 7 Days, 120 F., 14 Days, 120 F., Cone. of R.H. 50% R.H. Feature Addenda Feature Addenda Rel. Rel. Rel.

Speed 7 Fog Speed '7 Fog Speed '7 Fog Control 0 100 1.25 .16 19 .60 1.09 Methyl L-arabonate tetiaacetate 30 105 1.30 09 95 1. 20 15 Control 0 100 1.35 .14 39 1.13 D-Arabono-y-lactone 45 94 1.27 .08 96 1.23

Control 0 100 1.28 .15 69 1.00 IsobutylD-arabonate tetraacetate 45 102 1.33 .13 80 1.13 Methyl(tetraacetyl-D-arabonyl)glycolate 45 100 1.27 .12 78 1.10

Control 0 100 1.50 .15 37 1.13 D-Gluco-D-gulo-heptono-- -lactone 45 94 1.45 .10 73 1.23 D-Gluco-D-gulo-heptonoamide .1 45 100 1.55 .12 82 1.22

Control 0 100 1.60 .16 87 1.13 Methyl D,L-glycerate 45 89 1.55 .11 74 1.20

Control 0 100 1.35 .14 39 1.13 Dimethyl D-tartrate 45 94 1. 23 .07 94 1.13

00mm 0 100 1.35 .14 89 1.13 .25 1s .32 .93 D-Glucono-5-lactone 45 83 1.35 .07 89 1.30 .05 62 1.30 .08

Control 0 100 1. .16 87 1.13 .25 3o .90 .32 D-Gluconamide 45 100 1.50 .12 73 1.28 .12 73 1.12 .12

Control 0 100 1.23 .15 32 1.04 .25 50 .31 .52 D-Gluco-D-gulo-heptonie acid hexaacetate monohydrate. 18 83 1. 27 10 1.03 10 60 97 10 L-Erythronic acid tribenzoate 18 60 1.13 .12 53 1.02 .13 52 .95 .15

Control 0 100 1.33 .17 74 1.14 .24 29 .73 .33 D-Galactonic acid pentaacetate 28.5 85 1.43 .14 74 1.30 .12 60 1.12 .11

Data similar to that illustrated in Table A above was also obtained with hydroxy carboxylic acid derivatives of the 60 invention listed in Table B *below when incorporated in the silver halide emulsion described above, and thereafter incubated, exposed and processed as described above. Subg gg u'D'galactopyranoslde)uron'ate 45 stantially reduced fog levels without objectionable reduc- D 3 10 6 tion in speed were obtained in each instance after the in- 5 D i 13 5 cubation period as compared to the same emulsion conggzi g gg tainin no feature h drox carbox lie acid derivative.

g y y y D-rrbomc acid tetraacetate 26.55 TABLE 3 Cone of L-erythronamide 45 D-ribono- -lactone 45 feature addenda 7 Feature addenda: (g./mole AgX) Example 2 L-arabono-v-lactone 45 For purposes of comparison, sevenal compounds closely D,L-arabono-'y-lact0ne 5 related to the antifoggant addenda of the invention were D-arabonamide 45 incorporated into the high-speed gelatino silver halide Methyl D,L-arabonate 5 emulsion described in Example 1, and thereafter incubated, exposed and processed as described in Example 1. The results are summarized by the data in Table C below.

invention asdescribed hereinabove and as defined in the appended claims.

TABLE Fresh Test 7 Days, 120 F., 14 Days, 120 F., Cone. of 50% RH. 50% RH. Feature Addenda Feature Addenda Rel. Rel. Rel.

Speed 7 Fog Speed '7 Fog Speed 7 Fog Control 0 100 1. 28 Sucrose 45 105 1. 45 Glucuronic acid.. 45 97 1. 33

Control 0 100 1.20 D-Glucose 45 107 1.33

Control 0 100 1.15 D-Arabonie acid 45 107 1.12 D-Arabonic acid potassium salt 45 97 1.10

Control 0 100 1.60 Methyl a-D-galactopyranuronat 42. 75 95 1.42 Methyl 2-ketogulonate 91 1.50

Control 0 100 1. 60 Methyl glucolate 45 100 1.52

Control 0 100 1.28 Ethylene bis(D-arabonate tetraacetate) 45 68 .92

Examples 3 and 4 below describe the preparation of I claim: two typical addenda of the invention. Other addenda of 1. A photographic silver halide emulsion containing the invention can be prepared by methods described in a hydroxy carboxylic acid derivative antifoggant having the literature set out above. a formula selected from the group consisting of 0 Example 3.(D-arabono-'y-lactone) ll f Twenty-five g. (0.122 mole) of potassium Darabonate (CHM),, d and ((3112).. was suspended in 75 ml. of n-butyl alcohol in a 200 ml. H l A Erlenmeyer flask. Gaseous, dry hydrogen chloride was 1 bubbled into the mixture, with cooling in an ice-water ((IJHNDO bath since considerable heat was generated. After 10 X minutes, introduction of hydrogen chloride was stopped, wherein. and the prec1p1tat e of potassium chloride was sepa t (l) M and Z are each selected from-the group consistby suction filtration. The precipitate was r1nsed with ing of a hydroxy radical and an acyloxy radical 25 ml. of hot n-butyl alcohol. The combined filtrates were having the formula concentrated in vacuo on a steam bath leaving a residue 40 O of a sirup which crystallized quickly on cooling. After standing overnight, the crude product was collected, amounting to 18 g. or 100% of the theoretical yield wherein R is selected from the group consisting of and melting at 96 to 98 C. The crude product was an alkyl radical and an aryl radical; recrystallized from a mixture of acetone and ether, MP. (2) X is selected from the group consisting of a 98 C. hydrogen atom, a carbinol radical, a radical having the formula Example 4.--(Isobutyl D-arabonate tetraacetate) 0 To a solution of 4.15 g. (0.0118 mole) of D-arabonyl CHaoiiRz chloride tetraacetate in 50 ml. of chloroform was added Where"! R2 15 Selected from the g p conslstll'lg 4 g. of isobutyl alcohol and 4 g. of pyridine. The reacof alkyl TadlCal and an y radlcfllt tion became warm. After standing overnight, the chloro- Y 135 slected frOm the PP conslstmg Q a form solution was extracted successively with water, dilute P fadlcal, a cafbamyl radical and a radlcal hydrochloric acid, dilute sodium bicarbonate solution and lng the formula water. The aqueous extracts were each extracted with chloroform. The combined chloroform portions were 4501p isiisfizseias sti e.an sth sia?.22: R1 an removed in vacuoyl i g F X f 5 ta] (4) A is selected from the group consisting of a ea 1 51 i 6 Y5 8 ap carbinol radical, a carbamyl radical, a carboxy radipeared on the edge of the sirup after standing for several C 31 a radical having the formula days. Scratching with a glass stirring rod then hastened crystallization of the waxy solid. After standing overnight in a refrigerator, the hardened crude product, meltdOR mg 96% of the i wherein R is an alkyl radical and a radical having cal yield. Recrystallization three tlmes from a mixture the formula of ether and low boiling ligroin did not alter the melting 0 point.

The invention thus provides new and useful photo- "CHiOCRz graphic silver halide emulsions, and which emulsions have wherein 2 is selected from the gmup consisting of high resistance to the formation of fog.

The invention has been described in considerable detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the an alkyl radical and an aryl radical; (5) m is an integer of 2 to 3; (6) n is an integer of l to 5; and (7) o is an integer of 0 to 2; except that at least one of A, Y and Z forms a radical 9 selected from the group consisting of a carbamyl radical and an ester radical. l 'i i T f I 2. A photographic silver halide emulsion containing a hydroxy carboxylic acid derivative antifog'gant having the formula wherein p is an integer of 2 to 3.

4. A photographic silver halide emulsion containing a hydroxy carboxylic acid derivative antifoggant having the formula HQOH wherein q is an integer of 1 to and R is an alkyl radical having 1 to 2 carbon atoms.

5. A photographic silver halide emulsion containing a hydroxy carboxylic acid derivative antifoggant having the formula 0 Low (dHOHh wherein q is an integer of 1 to 5.

6. A photographic silver halide emulsion containing a hydroxy carboxylic acid derivative antifoggant having the formula wherein q is an integer of l to 5.

7. A photographic silver halide emulsion containing a hydroxy carboxylic acid derivative antifoggant having the formula n CH0 0 R3) q wherein q is an integer of l to 5 and R is an alkyl radical having 1 to 8 carbon atoms.

1 0 8. A photographic silver halide emulsion containing a hydroxy carboxylic acid derivative antifoggant having the formula wherein q is an integer of 1 to 5 and R is a phenyl radical.

9. A photographic silver halide emulsion containing, a hydroxy carboxylic acid derivative antifo'ggant having the formula l? o-on o rroofim H1O CR3 wherein q is an integer of 1 to 5 and R is an alkyl radical having 1 to 8 carbon atoms.

10. A photographic silver halide emulsion containing a hydroxy carboxylic acid derivative antifoggant having the formula 0 d-OCH:

CHzOH wherein q is an integer of l to 5.

11. A photographic silver halide emulsion as described in claim 1 wherein gelatin is used as the dispersing agent for the silver halide.

12. A photographic silver halide emulsion as described in claim 1 wherein the silver halide is silver bromoiodide.

13. A photographic element comprising a photographic emulsion support having coated thereon a photographic silver halide emulsion as described in claim 1.

14. A photographic gelatino silver halide emulsion containing about 5 to grams per mole of silver halide in said emulsion of methyl L-arabonate.

15. A photographic gelatino silver halide emulsion containing about 5 to 100 grams per mole of silver halide in said emulsion of methyl D-arabonate.

16. A photographic gelatino silver halide emulsion containing about 5 to 100 grams per mole of silver halide in said emulsion of ethyl D-arabonate.

17. A photographic gelatino silver halide emulsion containing about 5 to 100 grams per mole of silver halide in said emulsion of D-arabono-y-lactone.

18. A photographic gelatino silver halide emulsion containing about 5 to 100 grams per mole of silver halide in said emulsion of D-arabonamide.

19. A photographic silver halide emulsion containing a hydroxy carboxylic acid derivative antifoggant selected from the group consisting of Diethyl mucate Methyl D-arabonate Ethyl D-arabonate Methyl L-arabonate tetra-acetate D-arabono-y-lactone Isobutyl D-arabonate tetra-acetate Methyl (tetraacetyl-D-arabonyl)glycolate D-gluco-D-gulo-heptono-'y-lactone D-gluco-D-gulo-heptonoamide Methyl D,L-glycerate Dimethyl D-tartrate D-glucono fi-lactone D-gluconamide D-gluco-D-gulo-heptonic acid hexaacetate monohydrate 1'1 L-erythronic acid tribenzoate D-galactonic acid pentaacetate L-arabono -lactone D,L-arabono-' -lactone D-arabonamide Methyl D,L-arabonate Ethyl L-arabonate Ethyl D,L-arabonate Methyl D-arabonate tetraacetate n-Propyl D-arabonate tetraacetate Isopropyl D-arabonate tetraacetate v 2,3,4,6-tetraacetyl-D-gluconic acid monohydrate D-galactono-y-lactone D-galactonamide Methyl D-galactonate Ethyl D-mannonate D-lyxono-v-lactone D-lyxonamide L-erythrono-y-lactone D-gluco-D-gu1o-hepton0'y-1actone 12 D-gluco-D-gulo-heptonamide Methyl D,L-glycerate Methyl L-arabonate v Methyl (methyl a-D-galactopyranbside)uronate monohydrate D-manno-y-lactone D-mannonamide D-glucono-y-lactone D-ribonic acid tetraacetate L-erythronamide and D-ribono-y-lactone.

References Cited UNITED STATES PATENTS 3,297,446 1/1967 Dun'n 96107 NORMAN G. TORCHIN, Primary Examiner.

J. R. EVERETT, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,396 ,028 August 6 1968 Wilbert J. Humphlett It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below: Column 2, lines 59 and 60, the formula should appear as sh below:

0 O u u (e .g., OCR, COR

Column 3, line 63, after "therein" insert in Column 4 line 52 "suports" should read supports Column 8 lines 28 to 35 the left-hand formula should appear as shown below:

Signed and sealed this 3rd day of February 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. I SCHUYLER, JR Attesting Officer Commissioner of Patents 

